Former members of U.S. special operations forces on Thursday demanded President Obama veto the budget bill Congress just passed, saying that the cuts to military retirement benefits — which even the bill’s authors now admit were a partial mistake — are an insult to veterans.

“As commander in chief, President Obama is the leader of the nation’s armed forces and he has a duty to protect the interests of all military members, both active and retired. He needs to veto the bill,” said Gary Stubblefield, a retired Navy SEAL Commander and chairman of Special Operations for America.

The new budget, which boosts spending in the short term in exchange for longer-term fee hikes and spending cuts, includes a provision that would reduce the cost-of-living adjustment for military retirees to 1 percent less than the rate of consumer inflation — and even reduces payments for veterans who were wounded in action.

It will go into effect in 2015 and is expected to save more than $6 billion over 10 years.

“It is shameful that the government is targeting the retirement pensions of men and women who put their lives on the line for their country,” Mr. Stubblefield said. “Congress needs to find a way to reduce spending without burdening our retired military with benefit cuts that are borne only by them, and not their civilian counterparts.”

The budget bill passed the House last week and the Senate on Wednesday, and will now head to Mr. Obama.

Sen. Patty Murray, chairwoman of the Senate Budget Committee and one of the chief authors along with House Budget Committee Chairman Paul Ryan, admitted the reduction in benefits for wounded veterans was a mistake.

Now the Washington state Democrat and other lawmakers have vowed to pass a fix — though it’s unclear whether it will cover all veterans or just the disabled.

Sen. Lindsey Graham, South Carolina Republican, is not willing to wait for standalone bills in 2014 and asked Mr. Obama to veto the bill until Congress had a fix.

“I would hope, Mr. President, you would hold the bill on your desk and send a message to the House and Senate: ‘I like your product, except this part. I’m going to hold the bill until you can find a fix,’” Mr. Graham said following the vote Wednesday night. “Mr. President, as commander in chief, I’m asking you not to sign this bill.”